Electron-deficient aromatic aldimine compound, preparation method and application thereof

Abstract

The application relates to the technical field of compound synthesis, and discloses an electron-deficient aromatic aldehyde imine compound, which is obtained by uniformly mixing an electron-deficient aromatic aldehyde compound or a heterocyclic compound with an amine compound and then performing a dehydration condensation reaction under heating conditions, the electron-deficient aromatic aldehyde compound, the heterocyclic compound and the amine compound are all chemical raw materials with wide sources, the reaction process is a one-pot reaction, the whole process is one-time feeding, and the separation step can be realized in the reaction process to obtain the final product, the reaction is convenient and efficient; and the application discloses application of the electron-deficient aromatic aldehyde imine compound in a polyurethane material system or a polyurea coating, the curing time is faster than that of a conventional latent curing agent, the efficiency is higher, the irritating odor of the conventional latent curing agent can be effectively eliminated, the application has important significance for improving a construction environment, conforms to the green environmental protection concept, and meets the needs of market and industry development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compound synthesis, and particularly relates to an electron-deficient aromatic aldimine compound and a preparation method and application thereof. BACKGROUND

[0002] Imine or oxazolidine refers to a product generated by eliminating one molecule of water after nucleophilic addition reaction of aldehyde or ketone containing carbonyl compound and amine under certain conditions, and is a reaction intermediate that can participate in various reactions and is ubiquitous in the field of organic chemistry. They can be stably stored under anhydrous gas conditions, and can undergo hydrolysis reaction to generate corresponding carbonyl-containing compounds and amine compounds when contacted with water vapor. -NH-R can generally react with -NCO groups in toluene diisocyanate (TDI) or diphenyl methane diisocyanate (MDI), so that the imine or oxazolidine can be used as a latent curing agent for polyurethane coatings, sealants and adhesives and other materials by using this property, avoiding the generation of carbon dioxide gas, and fundamentally solving the problem of easy bubble generation of one-component polyurethane, such as Figure 1 As shown, CO2 release during application can cause coating film defects, irritating odor, system stability and other problems.

[0003] CN 102660013A reports that formaldehyde, acetaldehyde, benzaldehyde, cinnamyl aldehyde and other aldehyde compounds are used as reaction starters, but the use of formaldehyde, acetaldehyde and the like as starting materials will release substances harmful to the human body; CN 109251292A uses butyl aldehyde and propyl aldehyde as starting materials, but butyl aldehyde is a flammable liquid, and propyl aldehyde has a low flash point, which will release volatile and irritating odors during the reaction curing process; the curing agent disclosed in CN 107787337A uses aliphatic aldehyde or ketone such as propyl aldehyde and pentyl aldehyde, and these curing agents will release ketone or aldehyde volatile substances during the hydrolysis process. Therefore, although the one-component polyurethane waterproof coating added with the latent curing agent reduces or even eliminates the generation of bubbles, it also brings the problem of strong irritating odor, as shown in Figure 2 Especially, the one-component polyurethane coating is mainly applied to spaces with poor air circulation such as underground space, water storage engineering and kitchen and bathroom, so that the strong odor released during the curing process is more obvious, which may cause physical discomfort to the construction personnel and seriously affect the construction experience of the one-component polyurethane waterproof coating;

[0004] In addition, since the ketone or aldehyde compound released by the curing agent in the hydrolysis process remains in the cured film, the viscosity, stability of the coating and the physical and mechanical properties of the cured film also need to be investigated. EP2356189B1 and US6136942A disclose oxazolidine and imine curing agents using lily aldehyde and phenoxy-substituted benzaldehyde as starting materials, which are applied to aldehyde imine and cause the initial viscosity of the coating to increase significantly, greatly increasing the difficulty of construction and reducing the economy. CN1678653A, CN101883753A and CN102224181A disclose imine curing agents containing ester and amide groups using aliphatic aldehyde as starting material, which show viscosity increase after heat aging during use, resulting in decreased stability. US4853454 discloses a one-component polyurethane composition using substituted trimethylacetaldehyde imine as a curing agent, which has a lower odor due to the high vapor pressure of trimethylacetaldehyde, but an unpleasant odor can still be felt when using trimethylacetaldehyde imine, and the physical and mechanical properties of the coating film are low. SUMMARY

[0005] Therefore, the present application provides an electron-deficient aromatic aldehyde imine compound which is used as a latent curing agent in polyurethane coatings to effectively solve the problem of strong irritating odor of the latent curing agent in existing polyurethane coatings.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] The first object of the present application is to provide an electron-deficient aromatic aldehyde imine compound, which is shown as formula IV or formula V:

[0008]

[0009] wherein R 1 to R 5 each is independently and at least one is selected from any one of hydrogen (-H), halogen (-F, Cl, Br), trifluoromethyl (-CF3), halogen formyl (-CCl3), formate (-COCH3), sulfinate (-SO2CH3), sulfonate (-SO3CH3), amido (-CO2NH-), nitro (-NO2);

[0010] Het is a C4-C9 heterocyclic aromatic group containing O, S and N atoms, or a C4-C9 heterocyclic aromatic group substituted with halogen (-F, Cl, Br), trifluoromethyl (-CF3), halogen formyl (-CCl3), formate (-COCH3), sulfinate (-SO2CH3), sulfonate (-SO3CH3), amido (-CO2NH-), nitro (-NO2).

[0011] Preferably, in the above electron-deficient aromatic aldehyde imine compound, the compound comprises the following structure:

[0012]

[0013] A second object of the present application is to provide a preparation method of the above electron-deficient aromatic aldehyde imine compound, comprising the following steps:

[0014] The electron-deficient aromatic aldehyde compound or the heterocyclic compound is mixed with the amine compound, and then a dehydration condensation reaction occurs under heating to obtain the electron-deficient aromatic aldehyde imine compound.

[0015] Preferably, in the above preparation method, the structures of the electron-deficient aromatic aldehyde compound, the heterocyclic compound, and the amine compound are respectively shown in Formula I, Formula II, and Formula III:

[0016]

[0017] That is, the synthetic reaction formula of the electron-deficient aromatic aldehyde imine compound comprises:

[0018]

[0019]

[0020] Preferably, in the above preparation method, in the amine compound, A, B, and C are integers of 1-10, and are further preferably integers of 1-5; D is an integer of 0-10, and is further preferably an integer of 0-3; R 6 and R 7 are each independently selected from -H or a branched or alicyclic chain containing 1-6 carbon atoms; and X is -CH2- or -NH-.

[0021] Preferably, in the above preparation method, the amine compound is a binary chain aliphatic amine or a binary alicyclic amine compound containing two amino end caps and containing or not containing a branched chain in the middle;

[0022] The binary chain aliphatic amine includes ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, butanediamine, pentanediamine, 2-methylpentanediamine, hexanediamine, and polyether amine.

[0023] The binary alicyclic amine includes isophorone diamine (IPDA), diamino dicyclohexyl methane (PACM), dimethyl diamino dicyclohexyl methane (DMDC), bis(4-aminocyclohexyl) ether, and 1,3-cyclohexanediamine.

[0024] Preferably, in the above preparation method, the amine compound is a compound containing three amino groups, with or without substituents in the middle, including diethylenetriamine, N,N-bis(3-aminopropyl)methylamine, 3,3'-diaminodipropylamine, bis(hexamethylene)triamine, and N,N-dimethyl dipropylene triamine.

[0025] Preferably, in the above preparation method, the molar ratio of the electron-deficient aromatic aldehyde compound to the amine compound is 1.0:(0.5-1.0).

[0026] The molar ratio of the heterocyclic compound to the amine compound is 1.0:(0.5-1.0).

[0027] Preferably, in the above preparation method, the temperature of the dehydration condensation reaction is 80-150°C, and the time is 4-15h; further preferably, the temperature of the dehydration condensation reaction is 90-120°C, and the time is 6-12h.

[0028] Preferably, in the above preparation method, the dehydration condensation reaction is carried out in a closed reaction device or a reaction container with an additional condensation reflux device.

[0029] Preferably, in the above preparation method, further purification is included, specifically: during the reaction, the water produced by the dehydration condensation reaction is transferred to a receiving container under reduced pressure and vacuum, driving the reaction to proceed in the forward direction, and when no reaction water is detected and the reaction reaches the end point, the purified electron-deficient aromatic aldehyde imine compound is obtained.

[0030] Preferably, in the above preparation method, the vacuum degree of the reduced pressure and vacuum condition is -0.070 to -0.1 MPa, further preferably -0.080 to -0.095 MPa; if the vacuum degree is too low, the product has a higher water content and the reaction time is longer; and if the vacuum degree is too high, the reaction is too intense and it is difficult to control the reaction.

[0031] A third object of the present application is to provide an application of the above electron-deficient aromatic aldehyde imine compound in a polyurethane material system or a polyurea coating, wherein the polyurethane material system includes polyurethane coatings, sealants, or adhesives.

[0032] Specifically, the above electron-deficient aromatic aldehyde imine compound can be applied in coatings, sealants, or adhesives, and the principle of action is as follows:

[0033] The electron-deficient aromatic aldehyde imine compound forms an imine, and when the imine is hydrolyzed, the electron cloud density of the nitrogen atom of the imine is further reduced due to the electron-withdrawing effect of the electron-withdrawing group, and the electron cloud density of the nitrogen atom is more positive, at this time, the lone pair of electrons on the oxygen atom in the water molecule can more quickly or more easily attack the positive ion of nitrogen, and the reaction proceeds more quickly and more conveniently in the positive direction compared with the conventional non-substituted reaction; the reaction further proceeds through intramolecular electron transfer and the removal of the amino group, and finally releases aldehyde compounds and curing agent amine compounds, which further participate in the reaction of the coating;

[0034] The odor is the volatile substance produced by the diffusion of molecules to the air through Brownian motion, and the electrical signal produced by the combination of the nasal cavity receptor. The benzaldehyde released by the conventional latent curing agent is actually a spice, including cinnamyl aldehyde and piperonyl aldehyde. When the concentration is very high, it forms a pungent odor, but when it is diluted to a suitable concentration, it has the smell of jasmine. Therefore, the odor is greatly related to the concentration and saturated vapor pressure. When the odor concentration and saturated vapor pressure are lower, a slight odor or no odor can be produced. The electron-deficient aromatic aldehyde compound is an aromatic aldehyde substituted by an electron-withdrawing group, which increases the boiling point and reduces the saturated vapor pressure compared with conventional aldehydes. The corresponding aldehyde compound of the prepared latent curing agent is fixed in the coating or released extremely slowly after hydrolysis, which eliminates the large amount of release in a short time during the construction process from the source, and achieves the goal of greatly reducing the pungent odor of the product.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] (1) In the preparation process of the electron-deficient aromatic aldehyde imine compound, the electron-deficient aromatic aldehyde compound, the heterocyclic compound and the amine compound used are all widely sourced chemical raw materials, and the reaction process is a one-pot reaction. The final product can be obtained through a separation step during the reaction process after one-time feeding, and the reaction is convenient and efficient.

[0037] (2) According to the latent curing agent reaction mechanism, the hydrolysis speed of the electron-deficient aromatic aldehyde imine compound is faster, the curing time of the polyurethane coating after the application of the electron-deficient aromatic aldehyde imine compound is faster than that of the conventional latent curing agent, and the efficiency is higher. At the same time, the pungent odor of the conventional latent curing agent can be effectively eliminated. Due to the high activity of the electron-deficient aromatic aldehyde imine compound system, no additional solvent needs to be added when the electron-deficient aromatic aldehyde imine compound is added into the polyurethane coating, which avoids the addition of toxic, expensive and dangerous solvents, and no hazardous waste is generated after the reaction, which does not pollute the environment and has important significance for improving the construction environment, conforms to the green environmental protection concept, and meets the needs of market and industry development. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only only the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0039] Figure 1 is a schematic diagram of the curing mechanism of a single-component polyurethane material;

[0040] Figure 2 is a schematic diagram of the hydrolysis mechanism of a latent curing agent using an aldehyde or ketone compound as a raw material;

[0041] Figure 3 is a schematic diagram of the hydrolysis of an electron-deficient aromatic aldehyde imine compound;

[0042] Figure 4 is the nuclear magnetic resonance hydrogen spectrum of the target product obtained in Example 1;

[0043] Figure 5 is the nuclear magnetic resonance carbon spectrum of the target product obtained in Example 1;

[0044] Figure 6 is the infrared spectrum of the target product obtained in Example 1;

[0045] Figure 7 is the nuclear magnetic resonance hydrogen spectrum of the target product obtained in Example 2;

[0046] Figure 8 is the nuclear magnetic resonance carbon spectrum of the target product obtained in Example 2;

[0047] Figure 9 is the infrared spectrum of the target product obtained in Example 2;

[0048] Figure 10 is the nuclear magnetic resonance hydrogen spectrum of the target product obtained in Example 3;

[0049] Figure 11 is the nuclear magnetic resonance carbon spectrum of the target product obtained in Example 3;

[0050] Figure 12 is the infrared spectrum of the target product obtained in Example 3;

[0051] Figure 13 is the nuclear magnetic resonance hydrogen spectrum of the target product obtained in Example 4;

[0052] Figure 14 is the nuclear magnetic resonance carbon spectrum of the target product obtained in Example 4;

[0053] Figure 15The infrared spectrum of the target product obtained in Example 4 is shown in the following figure:

[0054] Figure 16 The hydrogen nuclear magnetic resonance spectrum of the target product obtained in Example 5 is shown in the following figure:

[0055] Figure 17 The carbon nuclear magnetic resonance spectrum of the target product obtained in Example 5 is shown in the following figure:

[0056] Figure 18 The infrared spectrum of the target product obtained in Example 5 is shown in the following figure:

[0057] Figure 19 The hydrogen nuclear magnetic resonance spectrum of the target product obtained in Example 6 is shown in the following figure:

[0058] Figure 20 The carbon nuclear magnetic resonance spectrum of the target product obtained in Example 6 is shown in the following figure:

[0059] Figure 21 The infrared spectrum of the target product obtained in Example 6 is shown in the following figure:

[0060] Figure 22 The hydrogen nuclear magnetic resonance spectrum of the target product obtained in Example 7 is shown in the following figure:

[0061] Figure 23 The carbon nuclear magnetic resonance spectrum of the target product obtained in Example 7 is shown in the following figure:

[0062] Figure 24 The infrared spectrum of the target product obtained in Example 7 is shown in the following figure:

[0063] Figure 25 A schematic diagram of the film forming effect of the polyurethane coating is shown in the following figure. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0065] Example 1

[0066] The present embodiment provides an electron-deficient aromatic aldehyde imine compound, and the structural formula is as follows:

[0067]

[0068] The preparation method is as follows: appropriate amount of 2-methyl pentanediamine and m-chlorobenzaldehyde are weighed in sequence, the m-chlorobenzaldehyde is added into a closed container with a condensation reflux device, then the 2-methyl pentanediamine is slowly added into the reaction system, heating and vacuum are started, the vacuum is controlled between -0.07 to -0.10 MPa, heating is started to 110℃ for 10 hours, after the reaction is completed, it is cooled to room temperature, and the target product (3a) is obtained. HRMS (ESI) Calcd. for C 20 H 22 Cl2N2([M+H] + ): 361.1233, Found: 361.1233.

[0069] As Figure 4 , 5 , 6 are the nuclear magnetic resonance hydrogen spectrum, carbon spectrum and infrared spectrum of the target product prepared in this example, respectively.

[0070] Example 2

[0071] This example provides an electron-deficient aromatic aldimine compound, and the structural formula is:

[0072]

[0073] The preparation method is as follows: appropriate amount of 2-methyl pentanediamine and m-chlorobenzaldehyde are weighed in sequence, the m-chlorobenzaldehyde is added into a closed container with a condensation reflux device, then the 2-methyl pentanediamine is slowly added into the reaction system, heating and vacuum are started, the vacuum is controlled between -0.07 to -0.010 MPa, heating is started to 100℃ for 11 hours. After the reaction is completed, it is cooled to room temperature, and the target product (3b) is obtained. HRMS (ESI) Calcd. for C 20 H 22 Br2N2([M+H] + ): 451.0203, Found: 451.0201.

[0074] As Figure 7 , 8 and 9 are the nuclear magnetic resonance hydrogen spectrum, carbon spectrum and infrared spectrum of the target product prepared in this example, respectively.

[0075] Example 3

[0076] This example provides an electron-deficient aromatic aldimine compound, and the structural formula is:

[0077]

[0078] The preparation method is as follows: Weigh appropriate amounts of propylenediamine and methyl formate benzaldehyde sequentially. Add methyl formate benzaldehyde to a sealed container equipped with a reflux condenser. Then, slowly add propylenediamine to the reaction system. Turn on heating and vacuum, controlling the vacuum between -0.08 and -0.095 MPa. Heat to 100°C and react for 9 hours. After the reaction is complete, cool to room temperature to obtain the target product (3c). HRMS(ESI)Calcd.for C 21 H 22 N₂O₄([M+H)) + ):367.1653,Found:367.1652.

[0079] like Figure 10 , 11 12 and 12 are the 1H NMR spectrum, 1C NMR spectrum, and IR spectrum of the target product prepared in this embodiment, respectively.

[0080] Example 4

[0081] This embodiment provides an electron-deficient aromatic aldehyde-imine compound with the following structural formula:

[0082]

[0083] The preparation method is as follows: Weigh appropriate amounts of pentanediamine and furan-2-carboxaldehyde sequentially. Add furan-2-carboxaldehyde to a sealed container equipped with a reflux condenser. Then, slowly add pentanediamine to the reaction system. Turn on heating and vacuum, controlling the vacuum between -0.08 and -0.095 MPa. Heat to 100°C and react for 10 hours. After the reaction is complete, cool to room temperature to obtain the target product (3d). HRMS(ESI)Calcd.for C 15 H 18 N₂O₂([M+H)) + ):259.1442,Found:259.1440.

[0084] like Figure 13 , 14 15 and 16 are the 1H NMR spectrum, 1C NMR spectrum, and IR spectrum of the target product prepared in this embodiment, respectively.

[0085] Example 5

[0086] This embodiment provides an electron-deficient aromatic aldehyde-imine compound with the following structural formula:

[0087]

[0088] The preparation method is as follows: appropriate amounts of 2-methylpentanediamine and 4-fluorobenzaldehyde are weighed in sequence, the 4-fluorobenzaldehyde is added into a closed container with a condensation reflux device, then the 2-methylpentanediamine is slowly added into the reaction system, heating and vacuum are turned on, the vacuum is controlled between -0.08 to -0.095 MPa, heating is performed to 120°C for 8 hours. After the reaction is completed, it is cooled to room temperature, and the target product (3e) is obtained. HRMS (ESI) Calcd. for C 15 H 18 N2O2([M+H] + ): 329.1824, Found: 329.1824.

[0089] As Figure 16 , 17 and 18 are the nuclear magnetic resonance hydrogen spectrum, carbon spectrum and infrared spectrum of the target product obtained in the preparation of this example, respectively.

[0090] Example 6

[0091] This example provides an electron-deficient aromatic aldimine compound, and the structural formula is:

[0092]

[0093] The preparation method is as follows: appropriate amounts of diamino dicyclohexyl methane (PACM) and m-chlorobenzaldehyde are weighed in sequence, the m-chlorobenzaldehyde is added into a closed container with a condensation reflux device, then the diamino dicyclohexyl methane is slowly added into the reaction system, heating and vacuum are turned on, the vacuum is controlled between -0.08 to -0.095 MPa, heating is performed to 120°C for 12 hours. After the reaction is completed, it is cooled to room temperature, and the target product (3f) is obtained. HRMS (ESI) Calcd. for C 27 H 32 Cl2N2([M+H] + ): 455.2016, Found: 455.2013.

[0094] As Figure 19 , 20 and 21 are the nuclear magnetic resonance hydrogen spectrum, carbon spectrum and infrared spectrum of the target product obtained in the preparation of this example, respectively.

[0095] Example 7

[0096] This example provides an electron-deficient aromatic aldimine compound, and the structural formula is:

[0097]

[0098] The preparation method is as follows: appropriate amounts of pentanediamine and thiophene-2-carboxaldehyde are weighed, the thiophene-2-carboxaldehyde is added into a closed container with a condensation reflux device, then the pentanediamine is slowly added into the reaction system, heating and vacuum are started, the vacuum is controlled between -0.08 and -0.095 MPa, heating is started to 100 DEG C for 10 hours. After the reaction is completed, it is cooled to room temperature, and the target product (3d) is obtained. HRMS (ESI) Calcd. for C 15 H 18 N2S2([M+H] + ): 291.0985, Found: 291.0986.

[0099] As Figure 22 , 23 and 24 are the nuclear magnetic resonance hydrogen spectrum, carbon spectrum and infrared spectrum of the target product prepared in this example, respectively.

[0100] The yield and purity of the target product prepared in examples 1-7 are summarized in table 1:

[0101] Table 1

[0102] Example Yield / % Purity / % Example 1 98.5 99.2 Example 2 98.7 99.3 Example 3 97.9 99.0 Example 4 99.1 99.1 Example 5 99.2 98.5 Example 6 96.9 98.1 Example 7 97.4 99.5

[0103] The electron-deficient aromatic aldehyde imine compound prepared in examples 1-7 is applied as a latent curing agent in a single-component polyurethane waterproof coating, and the formula is shown in table 2:

[0104] Table 2 Formula of single-component polyurethane waterproof coating

[0105]

[0106] Note: the amount of latent curing agent is replaced according to the equivalent amount of active ingredients.

[0107] The single-component polyurethane waterproof coating is prepared according to the following method: first, the polyether polyol, plasticizer, dispersant, various fillers are stirred and mixed, heated to 120 DEG C for 3 hours of dehydration, the water content is less than 0.03%, then cooled to 60 DEG C, the isocyanate is added and stirred uniformly, heated to 80 DEG C for 2 hours of reaction, the catalyst is added and continues to react for 1 hour, cooled to 65 DEG C, the latent curing agent and the remaining raw materials are added, cooled to 55 DEG C, vacuum degassing, sealed packaging, and the polyurethane waterproof coating is obtained and ready for use.

[0108] It should be noted that the formula of test examples 1-7 is one of the many formula compositions of polyurethane coatings, and the corresponding preparation method is also one of the many preparation methods of polyurethane coatings. The test examples of the present application are mainly to illustrate the improvement of the performance of polyurethane coatings by using the electron-deficient aromatic aldehyde imine compound as a latent curing agent, therefore the formula composition and preparation method of polyurethane coatings are not specially limited.

[0109] The polyurethane waterproof coating prepared from Test Example 1-7 and Comparative Example 1-2 was coated in a film frame, and after curing for 7 days under standard conditions (23 2 2 ℃, 50 2 10% relative humidity), the test was carried out according to the single-component type test method in GB / T 19250-2013 Polyurethane Waterproof Coating. The basic mechanical property test results of the polyurethane coatings of the test examples and comparative examples are shown in Table 3:

[0110] Table 3 Basic mechanical property test results of the polyurethane coatings of the test examples and comparative examples

[0111]

[0112] As can be seen from Table 3, the basic mechanical properties of all test examples and comparative examples meet the performance index requirements of GB / T 19250-2013 Polyurethane Waterproof Coating Single Component Type I. According to the different electronegativities of different substituents, the curing speed of the chlorine atom with higher electronegativity is faster than that of the bromine atom and the ester group substituted structure; the influence of different amines on physical and mechanical properties is different, and the tensile strength of the structure with good symmetry is high.

[0113] Test Example 1-7 and Comparative Example 2 use latent curing agents, and the film forming quality is good, flat and bubble-free, and the test example has a faster surface dry time and higher efficiency than Comparative Example 2; as shown in Figure 1, the left side is the film forming effect of the polyurethane coating of Test Example 1, which is flat, and the right side is the film forming effect of the polyurethane coating of Comparative Example 1, which has more pinholes and bubbles due to the absence of latent curing agents, although the performance meets the standard requirements. Figure 25

[0114] In addition, the odor performance of the polyurethane waterproof coatings prepared from Test Example 1-7 and Comparative Example 1-2 was detected according to the Chinese Building Materials Association Standard T / CBMF 118-2021 Building Material Product Odor Evaluation Method and T / CBMF 120-2021 Coating Product Odor Evaluation Method and Classification. The detection results are shown in Table 4:

[0115] Table 4 Odor performance test results of the polyurethane coatings of the test examples and comparative examples

[0116]

[0117]

[0118] ​As can be seen from Table 4, the polyurethane coating of the test examples 1-7 has low odor intensity and low odor concentration, has the same odor grade intensity as the comparative example 1 without adding the latent curing agent, and has basically the same odor concentration as the comparative example 1. Although the comparative example 2 has good film quality and mechanical properties, it releases unpleasant odor during the curing process of the coating, has the highest odor intensity grade, and also has the highest odor concentration. Therefore, the one-component polyurethane waterproof coating prepared by using the electron-deficient aromatic aldehyde imine compound as the latent curing agent achieves the purposes of rapid and efficient curing and effectively reducing odor.

[0119] In summary, by using the electron-deficient aromatic aldehyde imine compound as the latent curing agent, the problem of strong irritating odor of the existing latent curing agent, which harms the environment and the health of construction workers, is effectively solved. According to the standards of China Building Material Association, “T / CBMF 118-2021 Building Material Product Odor Evaluation Method” and “T / CBMF 120-2021 Coating Product Odor Evaluation Method and Grading”, the odor concentration of the product prepared by the method of the present application can be reduced by more than 80% compared with the conventional product, and the grade is reduced from 5 to 1.

[0120] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the solutions disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0121] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electron-deficient aromatic aldimine compound, characterized by, The electron-deficient aromatic aldehyde imine compound comprises any one of the following structures: 、 、 、 、 。 2. The electrophilic aromatic aldimine compound according to claim 1, wherein The electron-deficient aromatic aldehyde imine compound is prepared by the following preparation method: Electron-deficient aromatic aldehyde compounds The electron-deficient aromatic aldehyde compounds of claim 1 are obtained by mixing electron-deficient aromatic aldehyde compounds with amine compounds, and then performing a dehydration condensation reaction under heating, wherein the amine compounds are 1,2-propylenediamine, 2-methylpentanediamine, or diaminodicyclohexylmethane.

3. The electrophilic aromatic aldimine compound according to claim 2, wherein The molar ratio of the electron-deficient aromatic aldehyde compound to the amine compound is 1.0:(0.5-1.0).

4. The electrophilic aromatic aldimine compound according to claim 2, wherein The temperature of the dehydration condensation reaction is 80-150°C, and the time is 4-15h. And / or the dehydration condensation reaction is carried out under reduced pressure vacuum condition, and the vacuum degree of the reduced pressure vacuum condition is-0.070 to-0.1 MPa.

5. Application of the electron-deficient aromatic aldehyde imine compound in any one of claims 1-4 in a polyurethane material system or a polyurea coating.

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